Sound-reproducing needle



May 27 1924. l,495,609

N. c. OVAITT SOUND REPRODGING NEEDLE Original, Filed April 15 1918 I wat /WL/ym attenua/110 Patented May 217, 1924.

NELSON C. OVAITT, OF DETROIT, MICHIGAN.

SOUND-REPRODUCING NEEDLE.

Substitute for application Serial No. 228,605, led April 15, 1918. This application led July 1t), 1920;

Serial No. 395,281. Renewed March 3, 1924.

To ZZ whom t may concern:

Be it known that I, NELSON C. OvArrT, a citizen of the United States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful Improvements in Sound-Reproducing Needles, of which the following is a specification, reference being lhad therein to the accompanying drawings.

This invention relates to sound reproducing needles and refers more particularly to needles of the type used in honographs or similar musical playingv evices, the same being a substitute for the subject matter of applicants prior application filed April 15, 1918, Serial No. 228,605.

In phonographs or talking machines it is customary to employ a needle which travels in the groove of a record and there has been developed a needle -kno-wn as the tungsten or semi-permanent needle. Saidl needles, however, are defective, in that after they have been used a few times the friction between the needle and the record tends to wear the point of the needle flat on one side; then if the needle Vis removed and again 11e-inserted in the instrument it will not accurately reproduce unless put back into the holder in exactly the same position that it was when originallyfused. As such needles are usually provided with a 4cylindrical shank, it is extremely diilicult to return-the needle to its exact position.

The present invention particularly contemplates animproved needle construction wherein the needle is automatically positioned in the holder and can thus be removed and re-inserted numerous times without interfering with the sound reproducing qualities of the mechanism. A further very important feature of the invention is the arrangement whereby the shank ofthe needle isso formed that the end of the .needle cannot be' shoved into the seat far enough to contact with the end of the seat, thus avoiding the possibility of double vvibration caused by the contact-of the end of the needle .with the seat. Other objects of.

the invention are--to provide a construction whereby needles of the type' now on the market can be economically formed-'or constructed to automatically position themselves in the holders; and 'in general to provide a new and improved needle construction of the character above referred to.

In the drawings Figure 1 is a perspctive view of a soundbox of a phonograph, showing one of the needles in use;

Figure 2 is'an enlarged detail View of the needle; v

Figure 3 is a cross-section on the line 3 3 of Figure 2; and

Figure 4 is a view showing the manner in which the end of the needle is automatically kept outof contact with the end of the seat.

Describing in detail the particular elnbodiment of my invention shown in 'the drawings, A designates the tone arm of a sound reproducing device, such as a phonograph, and B the sound-box which is pivotally connected at C to the tone arm and is provided with a holder l) which has a triangular seat E into which the needle F is inserted. rlhe needle is locked in place by tightening up the thumb-screw G which advances the end I-I of the screw I-I against the needle F and forces it into clamping engagement with the sides E and E2 of the seat E.

Referring to the needle construction shown in detail in-F'igure 2, the needle- F comprises a main body or shank portion K in which there is suitably secured a fine playing point L. In previous constructions the shank K has been formed as a cylinder so that it could be inserted into the seat E in any one of a number of positions. While the type of needle shown and described is what is known as semi-permanent, it is often desirable toV remove it so that certain records can be played by fiber or other'needles,

after which thev semi-permanent needle is returned for further use. By my novel construction the tungsten needle can be taken ont and returned and upon its return will be automatically arranged with' reference to the holder so that it will be in substantially the same position that it was when originally used'.

For this purpose the shank K of the needle is formed with a lat face M which is engaged by the end H of the screw H when the thumb-screw Gr is turned -to lock the needle in the holder. While I have shown and described this face M as being dat, it is'of course understood that the invention is not limited to this particular shape and resides partly in the idea of providing a semi-permanent needle, of the type in which there are nok locating surfaces, with a surface which will definitely position it with reference to the holder. After the needle is inserted in place it is locked by tightening up the screw H in the usual manner and the needle can be removed and re-inserted a number of times Without in any Way changing the relative position ot the point L to the groove N of the disk N in which the needle point operates. Moreover in returning the needle it is only necessary to see that the flat side M is turned toward the end H of the screw, since when the latter is tightened up it Will automatically turn the needle to proper position of rotative adjustment. By this novel arrangement the needle can be removed and returned in the ordinary manner and the playing point always held in the same position with reference to the groove of the record.

As shown in detail particularly in Figure 4 the length of the fiat side M is less than the distance between the bottom E3 of the seat E and the end H of the screw H. Therefore, even though'the needle is shoved in as far as the fiat side. will permit, the end l of the shank l( will be held out of contact With the end E3 of the seatl. rll`his feature is important in that the needle is not only repositioned but it is automatically held out of contact with the end of the seat.

Various changes in the details of construction can of lcourse be made Within the scope of my invention.

l claim: l Y

l. ,The combination with a holder having a socket and a set-screw adapted to project into said socket, of a `needle having a shank tlattenedon one side, said flattened side being adapted to be engaged by the end of said set-screw, the length of said Hattened side being limited so as to prevent the end of the needle from reaching the end of the socket when the set-screw is in engagement with said flattened side.

2. rll`he combinationwith a holder having a socket and a set-screw adapted to project into said socket, of a needle having a shank provided with a locating surface, said locating surface being adapted to be engagedby the end' of said set-screw, the length of said locating surface being limit ed 'whereby the needle upon removal from the holder can be automatically returned to the same position lin the holder when the set-screw is adjusted ln testimony whereof ll aix my signature.

NnLsoN e ovaire. 

